1. Field of the Invention
The present invention relates to the containment and recovery of volatile liquids which have overflowed from tanker trucks.
2. Description of the Prior Art
Volatile liquid fuels are usually distributed from refinery to end user vehicles with at least two intermediate stages. The stages are usually by pipeline to regional bulk storage plants, and then by tanker truck from the bulk plant to filling stations. Whether loaded at a refinery, regional or local bulk plant, there is the potential for the accidental overfilling of tanker trucks, notwithstanding the use of automatic shut off mechanisms and other safeguards.
In U.S. Pat. No. 5,967,174 the present inventor addressed the problem of fuel spills which can occur upon filling top loading tanker trucks at small bulk plants. On such trucks a catch basin positioned on top of the tank around the tank inlet collected any spilled fuel and directed it toward drains at one end of the tank. A quick release hose could then be connected to the drain to divert fuel to a storage tank.
Problems with spills and overflows also occur at large fuel distribution farms, notwithstanding the greater sophistication of the equipment. Tankers loaded at fuel distribution farms tend to be side filling. Valves located at the top of the tanks allow fuel vapor to escape. Sensors located at the tops of the tanks are used to determine when liquid levels reach the tops of the tanks to automatically shut off fuel flow. Sometimes these sensors are inoperative, typically because of failure of associated electronics. When this occurs fuel can escape through the valves into channels running along the top of the trucks and from there into recovery basins. The prevention of release of fuel into the environment is best effected by preventing the release of fluid fuel as either liquid or gas.
The invention comprises an apparatus and method for recovering spills of volatile liquids overflowing from a mobile delivery tank. The mobile delivery tank has an inlet to the top of the mobile delivery tank, a vapor return conduit in fluid communication with the inlet, and a drain from the vapor return conduit, an open end of which drain is accessible from outside the mobile delivery tank. An external recovery tank is provided to receive that portion of the overflowing fuel still in liquid form. An overhead vapor recovery line receives the vapor portion. A Y or T-connector attaches to the open end of the drain, the connector including a branched element where one branch is connected to the overhead vapor recovery line and a second branch is connected to the recovery tank.
Additional effects, features and advantages will be apparent in the written description that follows.